Kymberly A. Gyure

Extracranial sinonasal tract meningiomas: a clinicopathologic study of 30 cases with a review of the literature

Extracranial meningiomas of the sinonasal tract are rare tumors. These tumors are frequently misclassified, resulting in inappropriate clinical management. To date, there has been no comprehensive study to evaluate the clinicopathologic aspects of meningioma in these anatomic sites. Thirty cases of sinonasal tract meningiomas diagnosed between 1970 and 1992 were retrieved from the files of the Otorhinolaryngic Registry of the AFIP. Histologic features were reviewed, immunohistochemical studies were performed, patient follow up was obtained, and the results were statistically analyzed. The patients included 15 females and 15 males, aged 13 to 88 years (mean, 47.6 yrs). Patients presented clinically with a mass, epistaxis, sinusitis, pain, visual changes, or nasal obstruction, dependent on the anatomic site of involvement. Symptoms were present for an average of 31.1 months. The tumors affected the nasal cavity (n = 14), nasopharynx (n = 3), frontal sinus (n = 2), sphenoid sinus (n = 2). or a combination of the nasal cavity and ethmoid, frontal, sphenoid, and/or maxillary sinuses (n = 9). The tumors ranged in size from 1.0 to 8.0 cm in greatest dimension (mean, 3.5 cm). Radiographic studies demonstrated a central nervous system connection in six cases. The tumors often eroded the bones of the sinuses (n = 18) and involved the surrounding soft tissues, the orbit, and occasionally the base of the skull. Histologically, the tumors demonstrated features similar to intracranial meningiomas. The majority were of the meningothelial type (n = 23), although there were three atypical meningiomas. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (EMA) and vimentin (all tested). The differential diagnosis includes paraganglioma, carcinoma, melanoma, psammomatoid ossifying fibroma, and angiofibroma. Surgical excision was used in all patients. Three patients died with recurrent disease (mean, 1.2 yrs), one was alive with recurrent disease (25.6 years), and the remaining 24 patients were alive or had died of unrelated causes (mean, 13.9 yrs) at the time of last follow up (two patients were lost to follow up). Extracranial sinonasal tract meningiomas are rare tumors which need to be considered in the differential diagnosis of sinonasal tumors. A whorled growth pattern and psammoma bodies, combined with positive EMA and vimentin immunohistochemical reactions, can confirm the diagnosis of meningioma. The overall prognosis is good, without a difference in outcome between benign and atypical meningiomas.

Foamy cells with oligodendroglial phenotype in childhood ataxia with diffuse central nervous system hypomyelination syndrome

Abstract Childhood ataxia with diffuse central nervous system hypomyelination syndrome (CACH) is a recently described leukodystrophy of unknown etiology. To characterize the neuropathological features and gain insight as to the pathogenesis of this disorder, we studied cerebral tissue from six patients with the CACH syndrome. Evaluation of toluidine blue-stained, semithin sections of white matter from CACH patients disclosed unusual cells with “foamy” cytoplasm, small round nuclei and fine chromatin. Electron microscopy (EM) revealed cells in the white matter with abundant cytoplasm containing many mitochondria and loosely clustered, membranous structures, but lacking the lysosomal structures seen in macrophages. Further analysis of tissue sections with antibodies and special stains demonstrated that the abnormal cells with abundant cytoplasm labeled with oligodendroglial markers, but did not react with macrophage or astrocytic markers. Double immunolabeling with macrophage and oligodendroglial markers clearly distinguished macrophages from the “foamy” oligodendroglial cells (FODCs). Proteolipid protein (PLP) mRNA in situ hybridization demonstrated PLP mRNA transcripts in a high proportion of oligodendrocytes in CACH patients compared to control patients, and PLP mRNA transcript signal in cells, morphologically consistent with FODCs. Normal and pathological brain control tissues did not contain FODCs. These neuropathological findings will be useful pathological identifiers of CACH, and may provide clues to the pathogenesis of this disorder.

Mycobacterial spindle cell pseudotumor of the brain: A case report and review of the literature

Spindle cell pseudotumors found in the skin, lymph nodes, bone marrow, spleen, lungs, and retroperitoneum have been reported recently in immunosuppressed patients, including those with acquired immunodeficiency syndrome. The authors report a similar lesion limited to the brain in a 38-year-old human immunodeficiency virus-negative man receiving steroid therapy for treatment of sarcoidosis. Histopathologically the lesions were composed of spindle and epithelioid histiocytes, small foci of necrosis, and numerous acid-fast bacilli. The acid-fast bacilli were determined by culture and polymerase chain reaction to be Mycobacterium avium intracellulare. Because of the uncommon histologic appearance of this lesion and the potential for treatment if recognized, mycobacterial spindle cell pseudotumors should be included in the differential diagnosis of spindle cell lesions in the brain in immunosuppressed patients.

A Clinicopathological Study of 15 Patients With Neuroglial Heterotopias and Encephaloceles of the Middle Ear and Mastoid Region

Objectives/Hypothesis Heterotopic masses of neuroglial tissue involving non‐midline structures, specifically, the middle ear region, are exceptional. The pathogenesis of these lesions and, in particular, their relation to encephaloceles, is uncertain.

Retroperitoneal peripheral hemangioblastoma: a case report and review of the literature.

Central nervous system hemangioblastomas are uncommon tumors of controversial etiology that are usually found in the posterior fossa of the cranial cavity, retina, and spinal cord. Peripheral involvement is rare; only isolated case reports have been identified. We report an unusual case of hemangioblastoma involving the retroperitoneum. A 47-year-old African-American man presented with polycythemia on routine laboratory testing. Computed tomography revealed a large retroperitoneal mass near the pancreas, in a left suprarenal location, without adrenal involvement and without attachment to a nerve. Although hemangioblastoma may be associated with the von Hippel-Lindau syndrome, this patient did not have any of the stigmata of this disease. The histologic features included a highly vascular tumor with cellular areas composed of plump, pleomorphic spindled and epithelioid (stromal) cells with variable cytoplasmic lipid vacuoles and hypocellular areas with inflammatory cells and collagenous fibrils. Immunohistochemical staining showed that the tumor (stromal) cells were positive for vimentin, calponin, S-100 protein, neuron-specific enolase, and CD57 and negative for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, CD34, HMB-45, desmin, and the actins. These morphologic and immunohistochemical findings are consistent with hemangioblastoma. To our knowledge this is the first reported case of a hemangioblastoma in this location. Based on this case we conclude that hemangioblastoma may occur in the retroperitoneum and outside of the central nervous system in a patient without von Hippel-Lindau syndrome. The immunoprofile of this case suggests that hemangioblastomas are mesenchymal neoplasms exhibiting both neural and myofibroblastic differentiation.

Dysembryoplastic neuroepithelial tumor: An immunohistochemical study with myelin oligodendrocyte glycoprotein

CONTEXT The dysembryoplastic neuroepithelial tumor (DNT) is an uncommon lesion characterized by a heterogeneous population of neurons, astrocytes, and oligodendroglia-like cells (OLCs). The basic nature of the DNT and its constituent cells, particularly the OLCs, remains unresolved; some authors favor a neuronal origin, and others propose a glial or mixed origin for these cells. DESIGN We examined 11 DNTs with antibodies to myelin oligodendrocyte glycoprotein, a marker of mature oligodendrocytes. RESULTS All DNTs studied (7 from males, 4 from females; age range of patients, 2-37 years) were composed of varying proportions of neurons, astrocytes, and OLCs. Membrane or cytoplasmic immunoreactivity for myelin oligodendrocyte glycoprotein was found in many OLCs in 9 of 11 cases. The number of myelin oligodendrocyte glycoprotein-positive OLCs was variable: >75% of the OLCs were positive in 5 cases, 25% to 75% of the OLCs were positive in 2 cases, and <25% of the OLCs were positive in 2 cases. CONCLUSION These findings suggest that many of the OLCs represent mature oligodendrocytes and support the notion that DNTs are heterogenous lesions composed of multiple, mature cell types.